News Service from House Harris

NSW: Man who killed girlfriend on trial over 'impairment'

SYDNEY, April 29 AAP - A man who killed his estranged partner says he saw "strobing" images of family members in his mind while he did it, a Sydney court has heard.

David Martin Valiukas, 43, from Mumbil in NSW's central west, has pleaded guilty to the manslaughter of Lisa Ann Clymer on the basis he was suffering substantive impairment.

A trial is underway in the NSW Supreme Court in Sydney, where a jury will have to decide whether Valiukas was suffering impairment so serious to warrant his liability for murder reduced to manslaughter.

The crown case is there's insufficient evidence Valiukas was suffering from a disassociated state which would have impaired his judgment at the time of the killing.

There is no issue he killed the 25-year-old at her Bradbury home, in Sydney's southwest, on or about September 21, 1999.

The court was told on Wednesday that Ms Clymer's remains were found in a shed at the back of Valiukas' mother's home in Mumbil on April 26, 2007, two days after he attempted suicide.

Ms Clymer had been reported missing in September 1999 and an inquest into her death was set down for the week her remains were discovered.

The court heard a post-mortem examination found she suffered injuries consistent with strangulation.

In her opening statement to the jury, crown prosecutor Margaret Cunneen SC read Valiukas' suicide note, in which he admits killing Ms Clymer.

In the note, Valiukas says the couple argued because he no longer wanted to have a sexual relationship with Ms Clymer, from whom he had been estranged for some time.

The note said Ms Clymer threw coffee on him and began to hit him.

"I closed my eyes seeing the faces of Lisa ... and my father strobing into my brain," he wrote.

"I struck out yelling 'stop it, stop it'. It seemed to me the next moment she stopped hitting me and I released her.

"She fell onto the bed, not breathing. I just stood there ... realising what I had done."

The court was also played a police interview with Valiukas from June 2002, in which he says Ms Clymer left the house after the argument and got into an unknown car.

Forensic pathologist Dr Paul Botterill, who examined Ms Clymer's remains, told the court her cause of death was undetermined but consistent with strangulation.

There was no skin left on the remains but a delicate bone in her neck had been broken, indicating the possibility Ms Clymer had been strangled, Dr Botterill said.

The trial continues before Justice Robert Hulme.